In biology, kingdom (Latin: regnum, pl. regna) is the second highest taxonomic rank below domain. Kingdoms are divided into smaller groups called phyla. Traditionally, textbooks from the United States used a system of six kingdoms (Animalia, Plantae, Fungi, Protista, Archaea, and Bacteria) while British, Australian and Latin American textbooks used five kingdoms (Animalia, Plantae, Fungi, Protoctista, and Prokaryota/Monera). Some recent classifications based on modern cladistics have explicitly abandoned the term "kingdom", noting that the traditional kingdoms are not monophyletic, i.e., do not consist of all the descendants of a common ancestor.